Tuesday, 27 August 2019

in which I decide to go Brompton electric


I realised I've had my Brompton bike for about 10 years. I'm not sure if the serial number is a clue to its age, because I suspect it might have the date built into it somewhere. I found some incriminating photographs of the S6L from a London Skyride back in 2009, then a picture of me unloading it from my car in Belgravia

and finally a picture of it parked outside Parliament, along the Thames.

Of all my bikes, this one has stayed the closest to its original configuration, through time. I once considered changing the saddle to a Brooks B17, but then I realised that the Brompton one with it has a special cushioned underside, which makes the bike easier to transport 'on the shoulder'.

Such is the cunningness of the design that just about every angle has been thought through. I joined the Brompton Users Group to read through the comments from other owners and I was struck by how many talked about journeys and/or bags rather than performsnce tweaks. That was until the electric version appeared and a few folk began to trial them.

Conventional story-telling says that the bike is for urban-dwellers and commuters, and that the electric version might be more for people who have trouble getting up hills. I was already convinced that the sheer utility of a bike that would fold down into my coupe car without knocking the seats down must be a force for good.

I also decided that if the e-bike could supplant some of the car journeys to shops, then it would have achieved some of the green-ness that my German car manufacturer was currently struggling to support.

So welcome to Brompton 2. It's known as a M6L, which is Brompton speak for a 'medium' handlebar, 6 speed (2 derailleur & 3 hub), with mudguards, not a rack. Oh yes, and it is electric. To a non-Bromptonite, the two bikes look almost identical.My first one has the slightly more compact 'sports' handlebar and is finished with silver bits. The electric comes in a choice of two colours only - black or white and for the black version, various parts have been additionally blackened (which was a paid option on the original bikes).

As luck would have it, I had a special voucher to get a significant discount on the bike, as long as I went to a particular bike store. That was a belated present from moving house, where the housebuilders gave various energy-saving inducements to the purchasers.

"Will you be riding it now?" asked the man in the shop, when I picked it up. He'd demonstrated the fold and the various buttons. I asked him if many went wrong.

"Truthfully, quite a lot at the beginning. They've sorted it out now and the software for us here in the bike shop is a lot simpler to use."

I said I'd be a chicken on this initial trip. I wanted to find a car park or somewhere quiet to try it out. We'd been on a bike trip recently and someone had a conventional e-bike which sped off suddenly when they were crossing a lock-gate. Ouch and emergency first aid to the leg.

My first impressions were actually pretty good. I was worried in case the bike would take off suddenly, but I discovered that pedalling seemed to be the only way that the motor would cut in and that then it was progressive. Brompton explain that they used some Williams (of F1 fame) engineering ideas when designing the motor and the torque and cadence sensor, which is built into the bottom bracket. The little black hub motor contains a planetary gear mechanism too, which no doubt makes the torque more controllable, via a fast revving engine that then gets geared down.



I like to think that some of the design thinking of the Brompton went upstream into the Williams FW-EVX platform, which they are trying to entice car manufacturers to adopt. The Brompton, at least, has the same battery cells, and the motor technology scaled down to 74mm width, based upon the chunky motors from the e-car.

Indeed, the general sensation of the bike feels like travelling on the pedal only one, only with 20 years younger legs. That difficult hill near the rec. ground? No longer. A reassuring quiet whirr can be heard whilst I pedal up it. Make no mistake though, if I stop pedalling, or apply the brakes the motor stops too.

So similar is the sensation, that I nearly had my own canal lock incident. Embarrassingly it was around the back of the bus stop shelter. I was doing a left-right zig-zag and slightly underestimated my acceleration. Nothing more than a screech to a halt, but it's reminded me to be aware.

The same thing happened in reverse, when I cycled from home to a nearby hill, was about halfway up it when I realised that I'd left the power off. Puff.

I conservatively opted for all 6 of Brompton's gears, despite various recommendations that I'd only need the 2-speed or 3-speed option. Embarrassingly, on this bike I usually select a gear and can more or less cycle everywhere in it.

Electric bikes in the UK (and Europe) have a legislated speed cut-off at 15.5 mph. Realistically, that's enough. If I wanted a motorbike, I'd have bought one. The bicycle needs to be able to keep up with traffic and potter amiably along cycle tracks. It's not about hardcore speed. My Garmin average speed is somewhere between 10-14 mph, so the bike still fits well with this. If I meander down to the river or the sea, then I'd put the speed even lower.

As well as the 6 gears, the Brompton has three power outputs from the motor: 1, 2 and 3. Honestly, I'm mainly using 1 at the moment. I guess I'm used to pedalling so the motor is probably providing a modest increase in watts. I'm also a bit chicken because of the possible increase in acceleration. This may sound daft, but I'm really quite keen to be 'in control' of the bike at all times.

I can tell that the design point for this bike is to set a power level and then stay with it. I've seen other bikes with handlebar-mounted speed controls, reminiscent of a throttle. I'm far more comfortable with the intelligence accorded through the bottom bracket sensing pedal revolutions and applying a suitable amount of extra torque progressively.

As for battery consumption. My longest trip out so far is about 15 miles. That's about two blips of five- 40% consumed? They say the range is 25-40 miles. I'd tend to agree with this and am anyway re-assured that the bike is quite usable without power, more or less handling as a standard Brompton.

And anyway, it feels much more like cycling. So, what do I think so far? Love it.

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